CN1073376A

CN1073376A - LF self-oscillation cavitation pulse jet nozzle and production method thereof

Info

Publication number: CN1073376A
Application number: CN 91110993
Authority: CN
Inventors: 陈国莲; 蒋学锋
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-12-17
Filing date: 1991-12-17
Publication date: 1993-06-23

Abstract

The present invention relates to a kind of rock bit that is suitable for, nozzle---the LF self-oscillation cavitation pulse jet nozzle and the production method thereof of PDC drill bit and other fixed cutter or the first-class usefulness of fire hose.The principal character of this nozzle is chamber wall 3 upper-thin-lower-thicks of resonance chamber 1, the angle of two uuper impinging surfaces 2 in the resonance chamber 1 is 110 °-130 °, the angle of two slower impinging surfaces 3 is 110 °-130 °, chamber wall 3 and uuper impinging surface 2, and the fillet between the slower impinging surface 4 is respectively R3, R1.5; Advantages such as the present invention compared with prior art has simple in structure, and effluxvelocity is bigger can improve rate of penetration by a relatively large margin.

Description

LF self-oscillation cavitation pulse jet nozzle and production method thereof

The present invention relates to a kind of rock bit that is suitable for, the nozzle-LF self-oscillation cavitation pulse jet nozzle of PDC drill bit and other fixed cutter or the first-class usefulness of fire hose, and the production method of this nozzle.

Supporting nozzle all is to adopt to go up the tapered straight-through inner chamber of big, following little unit on existing various oil bit and the mine drill bit, thereby is solid jet, and bit speed will improve 1% and all be difficult to; France, Germany utilize manually operated method that water is become the liquid bullet once at drilling well floor mounted valve switch, but in the dark down-hole of several kms, the one open-one close valve is difficult to, and may not become the liquid bullet to current; And existing nozzle production owing to nozzle is conical straight-through inner chamber thereby only needs general technology, sinters product into as entering high temperature sintering furnace after metallurgical powder stirring, the compression moulding.

Purpose of the present invention is exactly a kind of LF self-oscillation cavitation pulse jet nozzle that can avoid above-mentioned technical deficiency of design, and the process of producing this nozzle.

The objective of the invention is to realize: the LF self-oscillation pulse jet nozzle by following structure and principle, it is characterized in that it being the chamber wall upper-thin-lower-thick of resonance chamber of this nozzle, form up big and down small chamber shape, be subjected to the holding capacity of mud impact with the following fillet place that increases the nozzle stress concentration, prolong the application life of nozzle, the angle a1 of two uuper impinging surfaces in the resonator is 110 °-130 °, angle a2 between two slower impinging surfaces also is that the last fillet between 110 ° of-130 ° of chamber walls and uuper impinging surface is R3, and the following fillet between chamber wall and slower impinging surface is R1.5; Operating principle of the present invention be utilize continuous high-pressure spray through above-mentioned nozzle incident continuously in the low-frequency harmonics chamber, compression wave reflexes to uuper impinging surface through the chamber slower impinging surface, make the shear layer place that forms at the nozzle entrance place into jet that the lateral pressure fluctuation take place, and equate with the first phase of the compression wave that moves downward through the reflected pressure ripple of uuper impinging surface, form pressure.Antinode, crest overlap and form resonant condition, and this is an one.It two is through the higher order resonances cavity reflection, amplitude strengthens, increase 2-3 doubly in crest place dynamic pressure than jet inlet place average, pressure is reduced to negative pressure value at the antinode place, evaporation (gas that comprises molten Jie in the jet) rapidly takes place in fluid herein, forming minute bubbles is randomly distributed in the pulsing jet immediately, thereby formation cavitation pulse jet, it increases greatly to the erosion and the sharp wall fragmentation of rock mass, thereby improve mechanical bit speed (20-60%) significantly, footage per bit improves (16-56%).

The method of making this nozzle is: 1. elder generation makes nozzle interior resonator shape with the brass car and constitutes the internal mold of making nozzle.2. the nozzle internal mold is put into the nozzle external mold by upper punch and low punch location, then with 320-1000 purpose tungsten-carbide powder 46%, carbon is titanium powder 46%, tweezer powder 4%, cobalt dust 4% mixes all paraffin of back injection 8%, stir under 80 ℃ of temperature granular after, weighing 395g puts into the external mold that fills up nozzle, imposes 1-2 ton/cm ²The pressure press forming, baking dewaxing then; 3. in vacuum atmosphere, heat up 25 ℃ and kept 20 minutes after the shaping blank heating to 900 ℃ with per minute, to take off internal mold, after blank outer wall polishing shaping, heat up 30 ℃ to 1460 ℃ to the blank sintering with per minute again, keep temperature after 30 minutes, again with 45 ℃/minute be cooled to 100 ℃ with next can; On each nozzle, be carved with mark as need, can taking off internal mold and outer mill back remembers that with the electric spark blaze sintering then just heats up.

The present invention compared with prior art has can increase substantially mechanical bit speed, improve the advantages such as effect of the jet of its generation to the erosion and the wedge fragmentation of rock mass, wherein use this nozzle can make the instantaneous dynamic pressure of jet and effectively range improve 1.5-2.5 and 1.7-2.0 respectively doubly, and the planar radial that makes the shaft bottom speed that flows increases with its influence basin and bottom pressure gradient, adopt the drill bit of this nozzle can make rate of penetration improve 20-60%, footage per bit improves 16-56%.

Description of drawings of the present invention is as follows:

Fig. 1 is this nozzle arrangements schematic diagram;

The state diagram that Fig. 2 locatees in external mold for this nozzle internal mold;

Fillet on 1 resonance chamber, 2 uuper impinging surfaces, 3 chamber walls, 4 slower impinging surfaces, 5 among the figure, 6 times fillets, 7 upper punch, 8 upper punch locating holes, 9 location core bars, 10 external molds, 11 internal molds, 12 low punch locating holes, 13 low punches.

Below in conjunction with drawings and Examples the present invention is further described:

As shown in Figure 1, the principal character of LF self-oscillation cavitation pulse jet nozzle of the present invention is: chamber wall 3 upper-thin-lower-thicks of resonance chamber 1, form up big and down small shape chamber, chamber, to improve the ability that the anti-back wave in chamber bottom impacts, angle a1 in the resonator between the uuper impinging surface 2 is 110 °-130 °, angle a2 between the slower impinging surface 4 is 110 °-130 °, last fillet 5 between its uuper impinging surface 2 and the chamber wall 3 is R3, following fillet 6 between its slower impinging surface 4 and the chamber wall 3 is R1.5, equate with the first phase of the compression wave that moves downward with the reflected pressure ripple that reflects to form that reaches through uuper impinging surface 2, form compression wave, antinode, crest overlaps and forms resonant condition, to improve the effluxvelocity of nozzle, the method of producing this nozzle is: the resonator shape that 1 usefulness brass is made in the nozzle constitutes nozzle internal mold 11, brass can be with powder metallurgic method with brass powder compression moulding, and also available polycarbonate is injected into nozzle internal mold 11, and the finish of its internal mold exists More than 7,2 are positioned over internal mold in the external mold 10, by upper punch 7 low punches 13 and location core bar 9 with the internal mold positioning and fixing, with tungsten-carbide powder 46%, carbon is titanium powder 46% then, tweezer material end 4%, after cobalt dust 4% mixes, make the moulding additive with 8% paraffin and inject mixed-powder, itself and powder are stirred into granular, its 3959g of weighing puts into external mold again with 1-2 ton/cm ²Pressure be pressed into nozzle blank from bottom to top, as shown in Figure 2; 3. in vacuum drying oven, heat up 25 ℃ to shaping blank heating to 900 ℃ maintenance 20 minutes with per minute, make the internal mold liquefaction outflow in the nozzle blank reach the purpose of taking off inner membrance, in order to make stripping result better, the jet expansion of nozzle blank upwards can be placed, make convenient outflow of internal mold liquid after the liquefaction; With after the nozzle blank outer wall shaping polishing, available electric spark is carved the notes mark thereon, and then places vacuum drying oven to be warming up to 1460 ℃ of sintering nozzle blank after 30 minutes with 30 ℃/minute nozzle blank, again with 45 ℃/minute be cooled to 100 ℃ with next can.

Claims

1, a kind of LF self-oscillation cavitation pulse jet nozzle and production method thereof is characterized in that: chamber wall 3 upper-thin-lower-thicks of the resonator 1 of this nozzle form up big and down small chamber shape, the angle α of two uuper impinging surfaces 2 in the resonator ₁Be 110 °-130 °, the angle α of two slower impinging surfaces 4 ₂Be 110 °-130 °, the last fillet 5 between resonator chamber wall and uuper impinging surface is R3, and the following fillet 6 between resonator chamber wall and slower impinging surface is R1.5.

2, a kind of LF self-oscillation cavitation pulse jet nozzle and production method thereof is characterized in that: the method for making this nozzle is as follows:

A. the brass car is made this nozzle internal mold that is shaped as in nozzle interior resonance chamber 1, its fineness exists

More than 7,

B. the nozzle internal mold is put into the nozzle external mold and locate, then with 320-1000 purpose tungsten-carbide powder 46%, carbon is titanium powder 46%, and tweezer powder 4% cobalt dust 4% mixes and injects 8% paraffin, stirs into granular back weighing and puts into and fill up the nozzle external mold; Again with 1-2 ton/cm ²The pressure press forming,

C. in vacuum atmosphere, heat up 25 ℃ and keep 20 minutes to take off internal mold after the shaping blank heating to 900 ℃ with per minute, then to blank outer wall polishing shaping, remember with the electric spark blaze, again with per minute heat up 30 ℃ to 1460 ℃ the blank sintering kept 30 minutes after, be cooled to below 100 ℃ with 45 ℃/minute.

3, LF self-oscillation cavitation pulse jet nozzle as claimed in claim 2 and production method thereof is characterized in that: when the compacting blank, should upwards exert pressure from the nozzle below.

4, LF self-oscillation cavitation pulse jet nozzle as claimed in claim 2 and production method thereof is characterized in that: when internal mold is taken off in intensification to blank heating, the jet expansion of nozzle blank upwards should be placed.